Conventional television broadcasting systems include NTSC, PAL, and SECAM systems, and terrestrial waves, cables, and satellites have been used for effecting the broadcasting. Each of of these broadcasts are based on a single standard or format for the broadcast signal. For example, the NTSC system which is adopted in Japan and the United States is stipulates to perform interlaced scanning, with a frame rate of 29.97 Hz and 525 scanning lines per frame. Accordingly, receivers can therefore be manufactured simply and at low costs.
On the other hand, with an advance in the image compression technology, a recent trend is to apply such compression technology to the television broadcasting, and the use of MPEG (Moving picture Expert Group) 2 standard, which is now an international standard, is being contemplated. The MPEG 2 standard provides a high level of freedom in data compression, allowing video signals having a variety of formats to be dealt therewith. For example, ATV broadcast, which is planned in the United States is expected to to adopt a number of video formats, which are combinations of 750 or 1,125 scan lines, frame rate of 23.98, 24, 29.97, 30, 59.94 or 60 HZ, and interlaced or progressive scanning. This has a significance that a broadcasting video signal can be delivered in a video format which is optimum to the source material. To give examples, a progressive scanning having 1,125 scan lines and a frame rate of 24 Hz may be used for a movie source material, a progressive scanning having 750 scan lines and a frame rate of 60 Hz may be used for an animation or computer graphics, and an interlaced scanning having 1,125 scan lines and a frame rate or 30 Hz may be used for camera-taken source material.
As mentioned previously, a conventional television receiver is designed for use with a single standard or format of a broadcast signal, and hence is not provided with a capability to receive and display video signals of broadcasting or of a package medium, which are supplied in various formats. If the receiver is provided with an auto-scan monitor which is designed to select a size and a frame rate which conform to a particular video format, there are disadvantages that such a monitor is generally expensive, and a receiver having a large screen is difficult to manufacture, thus presenting a difficulty in its use as a television receiver. In addition, there is a problem that a video signal having a low frame rate, when it is used directly in the display, is likely to flicker, and there is also another problem that it does not lend itself for use in a television receiver which is frequently used in a bright place.